CP violations in lepton number violation processes and neutrino oscillations

There appear so many parameters and their mutual correlations in neutrino oscillation, beta (beta), and neutrinoless double beta ((beta)(O nu)) decays experiments. To get the constraints on these parameters we propose a graphical method which enables us to grasp the constraints effectively and intuitively. Th keep illustrative clearance, though this method is valid for more general case, we examine explicitly the case for the CP violating phase factors having +/-1 or +/-i. Some constraints derived from oscillation, beta and (beta)(O nu) decays experiments are also discussed.